How to Use the Initiative Database

The Miller-Rose Institute Initiative Database provides information on all of the 900+ statewide initiatives adopted in the U.S. from 1904-present. For each of these initiatives, the database provides the following information:

  • State
  • Year
  • Ballot number (where available)
  • Form of law (statute, constitutional amendment, or both)
  • Percent Yes vote
  • Subject category
  • Initiative summary

The menu on the left hand side of the database includes links to a table of all the initiatives, as well as lists grouped by state, category, and type. Within each of those grouping, you will be able to sort by any of the criteria by clicking on the column heading. Also, each field is fully indexed and can be search by through the “Search” button at the top of the table.

Initiative Litigation Data
In addition, the database provides the following information for post-election challenges to voter-approved initiatives:

  • State or Federal Court
  • Case Caption (including year)
  • Bases for challenge
  • Outcome (Upheld, invalidated in part, or invalidated in entirety)
  • Bases for decision

The post-election challenges can be found in the “Challenges” column of the initiative database. Initiatives with recorded challenges will display the number of challenges, which links to a table of the challenges themselves. These tables provide the same searching and sorting capability as the initiative tables.

Notes on the litigation data:

The database analyzes post-election challenges to the validity of voter-approved initiatives. It excludes cases that were filed prior to the election, or that sought judicial interpretation or enforcement of initiatives rather than their invalidation, or that were withdrawn, dismissed, or otherwise resolved without producing a reported decision. The outcomes are sorted into four categories: “upheld,” “invalidated in part,” “invalidated in entirety,” and “pending.” The distinction between “state” and federal” challenges is complicated when cases are filed in state courts but ultimately resolved in the federal courts. This happened most frequently when state challenges were reviewed by the U.S. Supreme Court. In the database, the category “state challenge” includes most cases filed in state courts but ultimately resolved by the U.S. Supreme Court. However, a few cases that originated outside of the five strongest initiative states then reached the U.S. Supreme Court are characterized as “federal.” The main example is U.S. Term Limits v. Thornton, 514 U.S. 779 (1995). That case originated in the Arkansas state courts, but produced a decision in the U.S. Supreme Court that struck down congressional term limits initiatives in all five of the states in this study. Finally, initiative challenges arising from criminal cases originally filed in state courts but later transferred to federal courts through petition for writ of habeas corpus are treated as federal challenges.

For more information on the database, contact Ken Miller at